Detachable windshield wiper blade unit

ABSTRACT

A flexible wiper element supported by a resiliently flexible backing strip. In some embodiments the wiper element and backing strip are bonded together. In other embodiments the backing strip includes a pair of transversely spaced strip members which retain the wiper element therebetween. Longitudinal edge portions of the backing strip are embraced by the usual claws of a wiper pressure unit, and longitudinally spaced detents are provided on the backing strip to releasably or snap-fittingly receive one of the claws between them, thereby to releasably hold the blade unit and pressure unit in assembled relation.

United States Patent Quinlan et al. 5] Nov. 14, 1972 [54] DETACHABLEWINDSHIELD WIPER 2,924,839 2/1960 Anderson ..15/250.42 BLADE UNIT3,393,419 7/1968 Scinta ..l5/250.42 Inventors: Wi liam J- Q nlan NorthTof wlse fee Drive; Lawrence L. Huver, llll North Boltwood Street, bothof Bummer-Peter Feldman Hastings, Mich. 4905 s Attorney-M11180 Cane [22]Filed: Oct. 14, 1971 [57] ABSTRACT [21] Appl' 189160 A flexible wiperelement supported by a resiliently Related Application Data flexiblebacking strip. In some embodiments the wiper 7 element and backing stripare bonded together. In [60] Dmslo? of N 5 1 332 other embodiments thebacking strip includes a pair of g z s gg 'g g g g is transverselyspaced strip members which retain the continuation-iri-part of Ser: No725 325 April wiper element therebetween' Longitudinal edge por- 30 1968Pat N o 3 541 629 tions of the backing strip are embraced by the usualclaws of a wiper pressure unit, and longitudinally s21 U.S. Cl..1s/2so.42 Spaced detems are Pmvided backing Strip [51] Int. Cl...B60s.1/02 releasably or preceive one of the claws 581 Field of Search..15/250.42, 250.36 between them, thereby to releasably hold the bladeunit and pressure unit in assembled relation.

[56] References Cited 26 Cl V 44 Drawing Fi UNITED STATES PATENTS2,687,544 8/1954 Scinta ..15/250.42

e T. ..a k a PMENTEDW 1 m2 3.702.490

SHEET 1 UF 6 20 Y 1? ll. /8 3/ 2/ 27 29 INVENTORS William J Quin/a giLawr nce 1.. Hum,

BY WW ATTORNEY PAIENTEDnnv 14 m2 SHEET 2 BF 6 M11121! Quin/4 1 LawrenceL/zuyer m5 ATTORNEY fii- PATENTEBM 14 HR SHEET 5 OF 6 229 LIZ? INVENTORWILLIAM J. QUINLAN a LAWRENCE L. HUVER BY WWW 04 ATTORNEY PATENTEDIMMM3.702.490 sum 6 0F 6 V234 W I z 233 (W INVENTOR 23s 9 WILLIAM-J. ouINLAWRENCE HUVER F/ 6. 44.

ATTORNEY DETACI-IABLE WINDSI-IIELD WIPER BLADE UNIT This is a divisionof application Ser. No. 90,938, filed Nov. 19, 1970 and is acontinuation-in-part of our allowed application Ser. No. 883,928, filedDec. 10, 1969, now U.S. Pat. No. 3,616,485 which in turn is acontinuation-in-part of our application Ser. No. 725,325, filed Apr. 30,1968 now U.S. Pat. No. 3,541,629, granted Nov. 24, 1970.

The invention relates to new and useful improvements in windshield wiperblade assemblies of the flexible type such as may be used on either flator curved Windshields, and in particular the invention concerns itselfwith certain improvements in blade assemblies utilizing a pressure unitwith a detachable blade unit.

An object of the invention is to provide a detachable blade unit whichmay be quickly and easily applied to or removed from the pressure unitand which is dependably held in assembled relation with the pressureunit without the use of separate parts such as clips, springs, screws,or the like, so that there is no possibility of such separate partsbecoming lost while the blade unit is being replaced.

Another important object of the invention is to provide an improvedblade unit consisting of a flexible wiper element supported by aresiliently flexible backing strip in such manner that the action of thepressure unit on the backing strip assures a proper wiping contact ofthe full length of the wiper element with either a flat or a curvedwindshield.

Another object of the invention is to provide the blade unit with ablade backing strip of novel construction which may be easily andeconomically manufactured and readily assembled with the wiper element.

U.S. Pat. No. 3,541,629 discloses a flexible wiper element supported bya resiliently flexible backing strip. In some embodiments the wiperelement and backing strip are bonded together. In other embodiments thebacking strip includes a pair of transversely spaced strip members whichretain the wiper element therebetween. Longitudinal edge portions of thebacking strip are embraced .by the usual claws of a wiper pressure unit,and longitudinally spaced detents are provided on the backing strip toreleasably or snapfittingly receive one of the claws between them,whereby to releasably hold the blade unit and pressure unit in assembledrelation.

U.S. Pat. No. 3,616,485 relates particularly to the blade backing stripwhich is provided with claw locking means comprising a pair oflongitudinally spaced detents including inclined portions to facilitateentry of a claw of the pressure unit in either direction into the spacebetween the detents, whereby the pressure unit is releasably locked inposition. Preferably means are also provided to permit or facilitateremoval of the claw from the locked position in either direction. Insome cases spring detents are employed which may be depressed to permitremoval of the claw; in other cases be understood from the followingdescription taken in conjunction with the accompanying drawings, whereinlike characters of reference are used to designate like parts, andwherein:

FIG. 1 is a side elevational view of a blade assembly including apressure unit and a blade unit;

FIG. 2 is an enlarged cross-sectional view of one embodiment of theblade unit;

FIG. 3 is a fragmentary side elevational view of the blade unit shown inFIG. 2;

FIG. 4 is a cross-sectional view of another embodiment of the bladeunit; v

FIG. 5 is a fragmentary view, partly in side elevation and partly inlongitudinal section of the blade unit of FIG. 4;

FIG. 6 is a fragmentary plan view of the backing strip used in the bladeunit of FIG. 2;

FIG. 7 is a fragmentary plan view of the backing strip used in the bladeunit of FIG. 4;

FIG. 8 is a fragmentary plan view of another embodiment of the backingstrip;

FIG. 9 is a fragmentary plan view of another embodiment;

FIG. 10 is a fragmentary plan view of another embodiment;

' FIG. 11 is a plan view showing another modification of the backingstrip;

FIG. 12 is a fragmentary plan view of another modification;

FIG. 13 is a plan view of still another modification;

FIG. 14 is a fragmentary plan view of another modification;

FIG. 15 is a fragmentary side elevational view of a blade unit using thebacking strip of FIG. 13;

FIG. 16 is a fragmentary side elevational view of a blade unit using thebacking strip of FIG. 1 1;

FIG. 17 is a fragmentary side elevational view showing a claw of thepressure unit applied to a blade unit utilizing spring detents on thebacking strip;

FIG. 18 is a cross-sectional view, taken substantially in the plane ofthe line 18-18 in FIG. 17;

FIG. 19 is a fragmentary sectional view, taken sub stantially in theplane of the line 1919 in FIG. 18;

FIG. 20 is a view similar to that in FIG. 19 but showing a modifiedarrangement of the spring detents;

FIG. 21 is a view similar to that in FIG. 18 but with the blade unit ofFIG. 2;

FIG. 22 is a fragmentary side elevational view showing a claw of thepressure unit applied to a blade unit utilizing boss type detents;

FIG. 23 is an enlarged fragmentary sectional detail of one of the bosstype detents;

FIG. 24 is a developed plan view of the backing strip of FIGS. 11 or 12,showing the same on a reduced scale and prior to its bending into shape;

FIG. 25 is a plan view similar to FIG. 11 showing a blade backing strip,but provided with pairs of detents in the form of cams located near oneend thereof and struck out from the material of the backing strip;

FIG. 26 is a fragmentary side elevation of a blade unit using thebacking strip of FIG. 25

FIG. 27 is a cross-section taken substantially in the plane of line27--27 of FIG. 26;

FIG. 28 is a plan view similar to FIG. 25, but with the pairs of camdetents located farther from the ends of the blade than in FIG. 25;

FIG. 29 is a fragmentary side elevation of a blade unit showing thebacking strip of FIG. 28;

FIG. 30 is a cross-section taken substantially in the plane of line30-30 of FIG. 20;

FIGS. 13-35 are diagrammatic views illustrating steps in the formationof the preferred type of backing strips;

FIG. 36 is a fragmentary perspective view showing one end of a backingstrip downturned to provide a wiper element stop;

FIG. 37 is a fragmentary elevational view showing the backing strip ofFIG. 36 assembled on a wiper element; 7

FIG. 38 a fragmentary group perspective view showing a modified backingstrip in which the strip members are overlapped;

FIG. 39 is-a fragmentary side elevational view of the backing stripmembers of FIG. 38 in their overlapped relation;

FIG. 40 is a fragmentary plan view of the subject shown in FIG. 39;

FIG. 41 is a fragmentaryv group perspective view showing anotherembodiment of the backing strip in which the strip members areoverlapped;

FIG. 42 is a fragmentary plan view of the backing 1 strip members ofFIG. 41 in their overlapped relation;

FIG. 43 is a fragmentary group perspective view of another embodiment ofthe backing strip with overlapped strip members; and

FIG. 44 is a fragmentary plan view of the backing strip members of FIG.43 in their overlapped relation.

Before describing the invention in detail it is to be noted that threebasic types of the blade unit are disclosed, each embodying a differentstructural combination of a wiper element and backing strip. Moreover,different types of longitudinally spaced detents are disclosed forreleasably holding a claw of the pressure unit assembled on a backingstrip of the blade unit of any one of the three basic types, and severalmodifications of the backing strip are also disclosed, any one of whichmay utilize either of the two types of releasable detents. For sake ofsimplicity of illustration only a few of the possible combinations havebeen shown in the drawings and it should be understood that variousother combinations are also possible.

Referring now to the accompanying drawings in detail, FIG. 1 shows awindshield wiper blade assembly consisting of two basic units, namely, apressure unit or super structure 11 and a blade unit or flexer assembly12, the blade unit being detachablyconnected to the usual claws 13 ofthe pressure unit so that the blade unit may be easily replaced.

In accordance with this invention means are provided to facilitateassembly or disassembly of the blade or flexer unit as will be morefully set forth hereinafter.

One suitable type of blade or flexer unit which may be employed inaccordance with the invention is shown in FIGS. 2, 3, 20 and 21, thesame comprising an elongated, flexible wiper element 14 made of rubber,or the like, which may be adhesively bonded as at to a backing strip 16.The backing strip, which may be made of metal, is resiliently flexiblein a plane normal to its surfaces, but is substantially rigid againstlateral or edgewise deflection. Thus, when the blade unit is applied tothe pressure unit 11, the flexibility of the backing strip as statedpermits the full length of the wiper element 14 'to properly contact thewindshield 17, regardless of whether the windshield is flat or hasvarying degrees'of curvature.

The backing strip of flexer 16 may be imperforate, but in order toenhanceits flexibility in a plane normal to its surfaces, the strip maybe providedwith a longitudinal row of perforations or slots 18 as shownin FIGS. 9 and 10. Alternatively, two ormore rows of such perforationsmay be provided, and the perforations in the two or more rows may beeither transversely aligned as shown in FIG. 6 or longitudinallystaggered as shown in FIG. 8. Also, if greater flexibility is desired inthe end portions of the strip than in the center portion thereof, theperforations may be provided only in the end portions and the centerportion may be left imperforate, as shown in the right-hand end of FIG.8. 4

It will be understood that various forms of perforations may be employedif .desired in connection with any of the types of backing strip orflexer herein disclosed or such perforations may be omitted if desiredwithout departing from the invention in its broadest aspect.

In any event, when the blade unit 12 is assembled to the pressure unit11, the claws 13 of the pressure unit slidably engage the longitudinaledge portions of the backing strip 16 as will be apparent from FIG. 21,whereby the blade unit is free to flex in passing over the windshieldcontour while the longitudinal distance or spacing between the clawsremains substantially the same. However, to prevent separation of theblade unit from the pressure unit by sliding, one of the pressure unitclaws is anchored'at a fixed point tothe backing strip 16 of the bladeunit by releasable detent means which holds the blade unit and pressureunit assembled but still permits the blade unit-to be detached whendesired for'purposes of replacement. Any one of the several claws 13 ofthe pressure unit may be used for such anchoring purposes by providingthereleasable detent means at an appropriate point alongthe length ofthe backing strip. I

Various different, selectively usable types of detent means aredisclosed, one of these being the spring detent type shown, for example,in FIGS. 6-11, 13 and 15-19. Here the longitudinal edge portions of thebacking strip are formed with transversely aligned pairs oflongitudinally spaced, substantially L-shaped slits 19 which are open atthe edges of the strip and define two pairs of spring detents 20. Thesespring detents are angularly offset as is best shown in FIGS. 15-17 soas to project outside the cross-section of the backing strip in adirection normal to the strip surfaces, and the longitudinal spacingbetween the spring detentsis substantially the same or slightly largerthan the longitudinal dimension of the pressure unit claw 13 which is tobe accommodated between the spring detents, as will be apparent fromFIG. 17. When the blade unit is applied to the pressure unit, the claws13 of the pressure unit are slid along the longitudinal edge portions ofthe backing strip until a selected one of the claws encounters a firstpair of transversely aligned spring detents. The detents 20 haveresilient characteristics which enable them to.

retract within the cross-section of the backing strip as the claw passesover them, whereupon they spring back to their normal, projectedposition and the claw is then retained in a seated or anchored positionon portions of the backing strip between the two pairs of springdetents. Thus the blade unit is held assembled to the pressure unit andwhen the blade unit is to be replaced, a pair of the spring detents areretracted to permit sliding of the claw outwardly from between the twopairs of detents and subsequent sliding separation of the blade unitfrom the pressure unit.

A slightly modified arrangement of the same type of spring detents isshown in FIG. 20, wherein the detents 20', rather than being offset in aplane normal to the backing strip surfaces, are offset laterally oredgewise in the plane of the strip surfaces, but otherwise the action ofthe detents is the same as already described. In this figure the claw 13is shown in locked position between the two sets of inclined springfingers 20',20'. To remove the claw the spring fingers are depressed asdescribed above.

A second type of releasable or snap-fitting detent means is shown, forexample, in FIGS. 10, 12, 22 and 23. The same comprises transverselyaligned, longitudinally space, concavo-convex bosses 21 which are formedat or closely adjacent to the longitudinal edges of the backing stripand project from one of the strip surfaces, as illustrated.

The longitudinal spacing of the detents 21 is substantially the same orslightly larger than the longitudinal dimension of the pressure unitclaw 13 which is to be seated between the detents in a manner similar tothe seating of the claw between the aforementioned detents 20 or 20'.However, the boss type detents 21 are not resilient in the same manneras the detents 20 or 20', and thus the detents 21 are carefullyproportioned in size and shape so that upon application of slidingpressure the claw may be forced over the detents which exert a camaction, either into a seated position between the detents when the bladeunit is being installed, or out of its seated position when the bladeunit is being removed. In any event, as in the instance of the springdetents 20 or 20', the claw is passed into its seated position with areleasable or snap-fitting action which holds the parts assembled untilthey are manually separated, which is facilitated by the roundedconfiguration of the bosses 21.

The releasable detent means 20, 20' or 21 may be provided intransversely aligned relation on both longitudinal edge portions of thebacking strip, or such means may be provided on one longitudinal edgeportion only, if so preferred.

A second type of blade unit which may be employed in accordance with theinvention is shown in FIGS. 4 and 5. Here the wiper element 14a has abody portion 22, a crown portion 23 and a cross-sectionally reduced neckportion 24, and the backing strip 16a (FIG. 7) is provided with alongitudinal row of openings or slots having the neck portion 24 of thewiper element extending therethrough. In manufacture, the wiper element14a may be extruded in a conventional manner while the backing strip 16ais being fed through the extruder, so that the two components becomeunitized by bonding of the crown portion 23 and of the neck portion 24to the backing strip. The openings 25 not only serve to accommodate theneck portion 24, but also enhance the resilient flexibility of thebacking strip as already explained in connection with the slots 18.

The backing strip'16a of the blade unit in FIGS. 4, 5 and 7 may beprovided with either the spring typedetent means 20, 20' or the bosstype snap-fitting detent means 21, as already mentioned.

Another type of blade assembly or unit of the invention is similar tothe second type in that it also utilizes the wiper element 140, but inthis instance the wiper element is extruded by itself and is theninstalled in a separate backing strip of which several modifications aredisclosed, as for example in FIGS. l1, l2, l3 and 14. The assembly isillustrated in FIGS. 15, 16, 17, 18, 19, 20 and 22.

The backing strip 26 of FIG. 11 is the preferred embodiment, the sameincluding a pair of transversely spaced strip members 27 and a pair ofclosed end portions 28 which bridge the strip members together. The neckportion 24 of the wiper element 14a is received in the space 29 betweenthe two strip members 27 and the end portions 28, disposed adjacent theends of the wiper element 14a, prevent longitudinal sliding of the wiperelement relative to the backing strip. Here again, the strip members 27may be fonned with openings 18 to enhance flexibility, and either thedetent means 20, 20' or the detent means 21 may be provided on the stripmembers, as desired, as exemplified in FIGS. 11 and 12, respectively.

The backing strip 26 is preferably formed from a single, strip-likepiece of material shown in its developed form in FIG. 24. Such a pieceof material is then formed by bending in the region of the lines 30 toprovide the end portions 28 when the backing strip assumes its closedconfiguration with the transversely spaced strip members 27, andmanufacture of the strip in this manner eliminates material waste suchas would otherwise be involved if the space 29 were blanked out of awider strip of material. It is to be particularly noted that when theterminal ends 31 of the material strip in FIG. 24 are brought togetheras in FIG. 11, they are left in an unattached, opposing relation, thatis, without being secured together. This not only permits the stripportions 27 to be spread apart for purposes of insertion or removal ofthe wiper element 14a, but it also permits a' certain amount of twistingof the wiper element at one side without transferring the load to theopposite side of the blade unit. The two free ends 31 are preferably cutat an angle which is oblique to the longitudinal axis, so that the endsmay lie in abutting relationship without any overlap and assist eachother in maintaining longitudinal alignment. It will be understood thatthe two strip members 27 are prevented from undue spreading laterallyaway from the neck portion 24 of the wiper element by the embracingengagement of the pressure unit claws l3 therewith.

In forming the L-shape spring detents 20 the following operations may beperformed:

1. The flexer rail or backing strip 26 consisting of a piece ofstainless steel is placed in a die which first pierces a rectangularhole approximately 0.028 inches in width and 0.187 inches in length,through the flexer rail or strip and close the outside edge of thelongitudinal strip leaving approximately 0.030 inches of stock betweenthe hole and the edge of the strip.

2. The next operation pierces the slot approximately 0.028 inches wideperpendicular to the first hole pierced and through the longitudinaledge strip; this removes the L portion from the rail, and the finaloperation angularly offsets the projections laterally approximately0.030 inches beyond the edge of the longitudinal strip.

It will be understood that in FIG. 11 the detents 20 are shown beforethey are angularly offset and in FIGS. 15, 16 and 17 they are shownafter the offsetting or bending operation. The detents may be formedeither before or after the strip 26 has been bent to the form shown inFIG. 11.

FIG. 13 shows a modified backing strip 26a which may be used in place ofthe strip 26. In this instance the two strip members 27a are formedseparately and include curved end portions 28a which are overlapped andsuitably secured together, as by spot welding, for example, to form theclosed ends of the backing strip. In another modification shown in FIG.14, the overlapped strip member end portions 28a are secured together bya rivet 32.

A further embodiment of the invention is shown in FIG. 25 wherein spacedcam type detents 120,120 are employed in connection with a backing strip126 similar to the backing strip 26 of FIG. 11, said strip comprisingspaced longitudinal strip members 127 formed by bending from a singlestrip of metal and having apair of closed end portions 128 which bridgethe strips together. The terminal ends 131 are interfitted with aL-shaped or stepped connection 132. v The cam detents 120,120 aregenerally similar in function and operation to the detents 20,20 and 21previously described in that they permit a claw 13 of the pressure unitto pass over one of said detents and enter the space between the detentswhere the claw is sustained in releasable locked position, from whichlocked position the claw may be removed by reverse action of the clawrelative to the detents.

As shown in- FIG. 25 the detents 120,120 are arranged in oppositelyspaced pairs near one end of the backing strip, though only onelongitudinally spaced pair is required. Each pair of cams 120'includesoppositely inclined leading cam edges 121 and 121' respectively slopingoutwardly from the adjacent longitudinal edge portion 122 of the backingstrip to permit entry of the claw 13 from either direction into thespace 123 between the detents 120.

Each pair of cam detents also includes steeply inclined cam portions 124and 124 sloping away from the edge portion 122 within the space 123 topermit removal of the claw 13 from the locked position in eitherdirection.

The pairs of detents 120,120 are preferably formed integral with theedge portions 122 of the backing strip in any suitable manner.Specifically the backing strip or flexer is placed in a die and as themetal is compressed it is forced downwardly and outwardly. On continuedapplication of pressure the cam becomes progressively thinner at itsouter portion as the lateral distance from the strip is increased.

The shape of the cam detents 120 is important. When the flexer assemblyor blade unit including the backing member or flexer strip carrying thedetents is positioned in the superstructure or pressure .unit 11 (FIG.1), the claw 13 of the superstructure acts as a cam follower. Theleading edges of the cams angles are low to permit ease of installation;and as the claw approaches the lobe the pressure is increasedand as theclaw passes the lobe the pressure is decreased placing the assembly inthe cam seat 123 or the locked position as shown in FIG. 26. The reverseaction removes the claw from the locked position allowing the assemblyto be removed from the superstructure.

As shown in FIG. 25 the pairs of cam detents 120,120 are locatedadjacent one end of the backing strip. FIG. 28 is similar except thatthe pairs of detents are located further away from the terminal endportions 131 than in FIG. 25.

It will be understood that the preferred form of backing strip as shownfor example in FIGS. 11, 12, 25 and 28 is formed from a singlestrip-like piece of material, preferably spring metal, whichis bentintermediate its ends to form a pair of strip members which areintegrally connected at one end and loosely fitting at their other ends.The locking detents which may be of the form shown for example in FIGS.11, 12, 25 and 28 may be formed either before or after bending thebacking strip and also the loose end portions may be shaped at anysuitable stage. This operation has been generally described inconnection with FIGS. 11, 12, 24 and 25 and will be more fully describedin reference to FIGS. 31-35 inclusive, wherein various steps inconnection with the formation of such backing strip will be set forth.

In FIG. 31 a single elongated strip of flexible spring metal isdesignated by the letter A. In FIG. 32 the strip A is shown as cut awayat B and shaped at its ends C prior to the bending operation illustratedin FIG. 33. Either before or'after bending pairs of detents D are formedfor coaction with the claws 13 of the superstructure as previouslydescribed herein. In FIG. 33 the detents are the type shown at 20 inFIG. 11 and are formed by first cutting out an L-shaped portion E afterwhich the spring detents D may be bent outwardly as previouslydescribedand as illustrated for example in FIGS. 15 and 20. In FIG. 34the pairs of detents D,D' are of the concave-convex boss type shown forexample in FIG. 12. In FIG. 35 the pairs of detent's'D",D" are of thecam type shown in FIGS. 25 and 28 and the free end portions C are shownas provided with a step fit as in FIGS. 25 and 28. As previouslyindicated the various types of detents may be formed at any stage of theoperation, either before or after the strip A (FIG. 31) has been bent tothe form shown in FIG. 33 and the detents may be of any suitable form asherein illustrated.

FIG. 36 illustrates a modified arrangement of the flexible blade backingstrip, which for all practical purposes may be any one of the typesshown in FIGS. 11, 12, 25, 28 and 31-35 in that the two strip members127 have a closed end portion 228. In this instance the end portion 228is downturned at right angles to the plane of the strip members and whenthe backing strip and a wiper element 14a are assembled as shown in FIG.37, the downturned end portion 228 abuts the adjacent end of the wiperelement and provides a stop to prevent sliding of the wiper element offthe ends of the strip members. Preferably, the downturned portion 228 isprovided at both ends of the backing strip to prevent sliding of thewiper element relative to the backing strip in either direction. It willbe appreciated that the backing strip members 127 may be provided withclaw locking means such as the detents in any one of FIGS. 1 1, 12, 25,28 and 31-35, as already indicated.

FIGS. 38-40 illustrate another modified embodiment of the flexible bladebacking strip, in which the free ends of the strip members 127 at oneend of the backing strip are overlapped, rather than being brought intoan opposing relation as in FIGS. 11, 12, 25, 28 and 31-35. As such, theembodiment of FIGS. 38-40 is somewhat related to those of FIGS. 13-15,but it is arranged difierently in that the end portion of each stripmember is shaped to provide a semi-circular end 228a terminating in anextension 229. The extension 229 is narrower than the strip member 127itself, being approximately of the same width as the material of the end228a.

After the wiper element 14 is inserted between the strip members 127,the strip members are brought together so that the extension 229 of onestrip member lies on top of the other strip member and the extension 229of the other strip member lies below the first strip member, as will beapparent from FIGS. 39 and 40. At the same time, the two free ends 228aare nested together, if they are downturned as suggested in FIG. 36 andalso shown in FIGS. 38-40, to provide stop means for the wiper element.However, the ends 2280 may lie flat in the plane of the respective stripmembers 127, rather than being downturned, in which event the ends 228asimply overlap each other. In either event, the arrow extensions 229 arelocated at the inner edges of the relatively wide strip members 127, aswill be apparent from FIG. 40. Any of the claw locking detents of FIGS.1 1, 12, 24, 25 and 31-35 may be provided on the strip members 127 inthe embodiment of FIGS. 38-40.

FIGS. 41 and 42 show another modified embodiment of the flexible bladebacking strip in which the free ends of the strip members 127 are alsooverlapped and in addition, claw locking means are provided on theoverlapped end portions rather than on the strip members themselves. Inthis embodiment each strip member has a substantially semicircular end228a terminating in an extension 230 which is of approximately the samewidth as the strip member itself, although the material of the end 2280is narrower so that a cam-edged step 231 exists at the junction of theend 228a with the extension 230. The terminal end of the extension 230is also cam-edged as indicated at 232.

The curvature of the end 228a is somewhat less than 180, so that when awiper element is inserted between the two strip members 127 and the freeend portions of the strip members are brought together in overlappingrelation as shown in FIG. 42, the extension 230 of each strip memberprojects angularly beyond the outer side edge of the other strip member.The claw locking means consist of a notch 233 cut into the outer edge ofeach extension 230, which notch forms a seat for the claw such as theclaw 13 in FIG. 1.

The free ends 228a of the strip members 127 are resiliently flexible sothat although the extensions 230 are normally outwardly projected beyondthe strip members as shown in FIG. 42, these extensions may be pressedinwardly as indicated by the arrows 234 when the claw is to be seated inor unseated from the notches 233. Thus, assuming a wiper element 14 andthe backing strip as having been assembled, theclaw may be passedlongitudinally over the end of the assembly as indicated by the arrow235. In the direction of the arrow 235 the extensions 230 have amutually divergent relationship, and as the claw passes over the steps231 and comes into engagement with the divergent outer edges of theextensions 230, these extensions will be pressed inwardly in thedirection of the arrows 234 until the claw snaps into the notches 233and becomes seated therein. If the claw is applied to the assembly in adirection opposite to that of the arrow 235, that is, in a directionfrom the opposite end of the backing strip, the extensions 230 may bemanually pressed inwardly as at 234 and the cam edges 232 will assist inpassing the claw over the extensions until it is seated in the notches233. The claw may be removed from the backing strip in either directionby manually pressing the extensions 230 inwardly to facilitate unseatingof the claw from the notches 233.

It may be noted that although each of the notches 233 has been referredto as providing a seat for the claw, it may also be regarded in terms oftwo longitudinally spaced detents for seating of the claw therebetween,if the longitudinally opposed edge portions of each notch are regardedas constituting individual detents. In this context the notcharrangement of FIGS. 41-42, and also of FIGS. 43-44 hereinafterdescribed, is comparable to the pairs of longitudinally spaced detentssuch as those in FIGS. 11, 12, 24, 25, 28 and 31-35.

It may also be noted'that although the ends 2280 in FIGS. 41-42 areshown as being flat and coplanar with the respective strip members 127,these ends may be downturned to provide stops for the wiper element, asfor example in FIGS. 36-40. The same is also applicable to thehereinafter described embodiment of FIGS. 43-44. g

The flexible blade backing strip embodiment of FIGS. 43-44 is related tothe embodiments of FIGS. 37 and 38 in that one of the strip members 127xis provided with an end 2280 and an extension 230 as in FIG. 43, whilethe other strip member 127y has a semi-circular end 228a with anextension 229, similar to FIG. 38. The end 228a and extension 229 arerelatively narrow in comparison to the width of the strip 127y, and theportion of the strip adjacent the end 228a is recessed or cut away as at236, so that it is of substantially the same narrow width as the end228a and extension 229.

When a wiper element 14 is inserted between the strip members 127x and127y and the free ends of the strip members are brought together intooverlapping relationship as shown in FIG. 44, the extension 229 of thestrip member 127y lies at the inner edge of the strip member 1271:,while the narrow, recessed portion 236 of the strip member 127y liesadjacent the inner edge of the extension 230 of the strip member 1271:,with sufiicient clearance between the recessed portion 236 and the inneredge of the notch 233 to permit the extension 230 to move inwardly inthe direction of the arrow 234 when a claw passes over the extension 230for seating in the notch 233.

The embodiment of FIGS. 43-44 is comparable to that of FIGS. 41-42 inthat the notched extension 230 constitutes the claw locking means whichin FIGS. 41-43 are duplicated at both sides of the backing strip, but inFIG. 43-44 are at one side only.

it is to be particularly noted that in all the embodiments of FIGS.36-44 where the strip members are equipped with the ends 228 or 228a andwith the extensions 229 or 230, the ends 228 or 228a extend around theadjacent end of the wiper element and each strip member with itsextension 229 or 230 engages the opposite sides of the neck of the wiperelement to securely hold it in place.

While in the foregoing there have been described and shown variousembodiments of the invention, other modifications may become apparent tothose skilled in the an to which the invention relates. Accordingly, itis not desired to limit the invention to this disclosure and variousmodifications and equivalents may be resorted to, falling within thespirit and scope of the invention as claimed.

What is claimed is:

1. For use in a windshield wiper blade assembly including an elongatedpressure unit and an elongated detachable blade unit; a blade backingstrip resiliently flexible in a plane normal to its flat surfaces butsubstantially rigid against lateral deflection, adapted to support aresiliently flexible wiper element, said pressure unit including aplurality of claws adapted to slidably engage longitudinal edge portionsof said backing strip at longitudinally spaced points, said backingstrip including claw locking means and means adapted to cooperate withone of said claws for releasably locking the blade unit against slidingrelative to the pressure unit, said claw locking means comprising a pairof longitudinally spaced snap-fitting detents provided on at least onelongitudinal edge portion of said backing strip, the spacing of saiddetents corresponding substantially to the longitudinal dimension ofsaid one claw, and said one claw being movable longitudinally of thebacking strip to snap-fit into and out of a seated position between saiddetents, said blade backing strip comprising a pair of strip memberstransversely spaced and unconnected from end to end and closed endbridging said strip members together at one end of the backing strip, apair of closed ends provided on the respective strip members at theother end of the backing strip, and an extension provided on each ofsaid pair of closed ends in transversely spaced relation from therespective strip members, the closed ends of the strip members with theextensions thereon being mutually overlapped to close said other end ofthe backing strip and prevent longitudinal sliding thereof relative to awiper element.

2. A flexible blade backing strip as defined in claim 1 wherein saidpair of longitudinally spaced detents are constituted by longitudinallyopposing edge portions of a single notch provided in an outerlongitudinal edge of the backing strip.

3. A flexible blade backing strip as defined in claim 1 wherein at leastone end of the backing strip is downturned and constitutes stop meansfor a-wiper element when assembled thereon.

4. A flexible blade backing strip as defined in claim 1 which is furthercharacterized in that it comprises a pair of strip members transverselyspaced and unconnected from end to end and adapted to receive a wiperelement therebetween, and a pair of closed ends bridging said stripmembers together adjacent the ends adapted to receive a wiper elementtherebetween, a v

of a wiper element, said closed ends being downturned from the plane ofthe backing strip and constituting stop means to prevent longitudinalsliding of the backing strip and wiper element relative to each other.

5. A flexible blade backing strip as defined in claim 1 which is furthercharacterized in that said closed ends of said strip members aredownturned from the plane of the backing strip and constitute stop meansto assist in preventing longitudinal sliding of the backing strip andwiper element relative to each other.

6. A flexible blade backing strip as defined in claim 1 wherein each ofsaid extensions is narrower than its as sociated strip member and isdisposed at the inner edge of the other strip member when said pair ofclosed ends of the strip members are overlapped.

7. A flexible blade backing strip as defined in claim 1 which is furthercharacterized in that said strip members with said closed ends and withsaid extensions are formed integrally from a single piece of material,the extension of each strip member overlapping but-being unconnected tothe other strip member.

8. A flexible blade backing strip as defined in claim 1 wherein saidclaw locking means are provided on the extension of at least one of saidstrip members.

9. A flexible blade backing strip as defined in claim 1 wherein saidclaw locking means are provided on the extensions of both of said stripmembers.

10. A flexible blade backing strip as definedin claim 1 wherein theextensionof at least one of said strip members normally retractablyprojects laterally outwardly beyond the outer edge of the other stripmember which is in overlapped relation therewith, the outer edge of saidprojecting extension being formed with a notch, longitudinally opposededge portions of said notch constituting said pair of detents of saidclaw locking means, between which detents a claw may be snap-fitted byretraction of said projecting extension.

11. A flexible blade backing strip as defined in claim 10 wherein saidprojecting extension is resiliently biased to its projected position bythe associated closed end of the associated strip member.

12. A flexible blade backing strip as defined in claim 10 wherein saidother strip member which is in overlapped relation with said projectingextension is provided with a cut away portion adjacent its closed end,said cut away portion being overlapped by said laterally projectingextension.

13. A flexible blade backing strip as defined in claim 1 wherein theextension of each strip member retractably projects laterally outwardlybeyond the outer edge of the other strip member which is in overlappedrelation therewith, the outer edge of each projecting extension beingformed with a notch, longitudinally opposed edge portions of said notchconstituting said pair of detents of said claw locking means, betweenwhich detents a claw may be snap-fitted by retraction of said projectingextensions.

14. A flexible blade backing strip as defined in claim 13 wherein saidprojecting extensions are resiliently biased to their projected positionby the associated closed ends of the respective strip members.

15.. For use in a windshield wiper blade assembly including an elongatedpressure unit and an elongated detachable blade unit; a blade backingstrip resiliently flexible in a-plane normal to its flat surfaces butsub-' stantially rigid against lateral deflection, adapted to support aresiliently flexible wiper element, said pressure unit including aplurality of claws adapted to slidingly engage longitudinal edgeportions of said backing strip at longitudinally spaced points, saidbacking strip including claw locking means and means adapted tocooperate with one of said claws for releasably locking the blade unitagainst sliding relative to the pressure unit, said backing stripcomprising a pair of strip members which are transversely spaced andunconnected from end to end and adapted to receive a wiper elementtherebetween, a closed end bridging said strip members together at oneend of the backing strip, a pair of closed ends provided on therespective strip members at the other end of the backing strip, and anextension provided on each of said pair of closed ends in transverselyspaced relation from the respective strip members, the closed ends ofthe strip members with the extensions thereon being mutually overlappedto close said other end of the backing strip and prevent longitudinalsliding thereof relative to a wiper element.

16. A flexible blade backing strip as defined in claim wherein at leastone end of the backing strip is downturned and constitutes stop meansfor a wiper element when assembled thereon.

17. A flexible blade backing strip as defined in claim 15 which isfurther characterized in that said closed ends of said strip members aredownturned from the plane of the backing strip and constitute stop meansto assist in preventing longitudinal sliding of the backing strip andwiper element relative to each other.

18. A flexible blade backing strip as defined in claim 15 wherein eachof said extensions is narrower than its associated strip member and isdisposed at the inner edge of the other strip member when said pair ofclosed ends of the strip members are overlapped.

19. A flexible blade backing strip as defined in claim 15 which isfurther characterized in that said strip members with said closed endsand with said extensions are formed integrally from a single piece ofmaterial, the extension of each strip member overlapping but beingunconnected from the other strip member.

20. A flexibleblade backing strip as defined in claim 15 wherein saidclaw locking means are provided on the extension of at least one of saidstrip members.

21. A flexible blade backing strip as defined in claim 15 wherein saidclaw locking means are provided on the extensions of both of said stripmembers.

22. A flexible blade backing strip as defined in claim 15 wherein theextension of at least one of said strip members retractably projectslaterally outwardly beyond the outer edge of the other strip memberwhich is in overlapped relation therewith, the outer edge of saidprojecting extension being formed with a notch, longitudinally opposededge portions of said notch constituting said pair of detents of saidclaw locking means, between which detents a claw may be snap-fitted byretraction of said projecting extension.

23. A flexible blade backing strip as'defined in claim 22 wherein saidprojecting extension is resiliently biased to its projected position bythe associated closed end of the associated strip member.

24. A flexible blade backing strip as defined in claim 22 wherein saidother strip member which is in overlapped relation with said pro ectingextension 18 provided with a cut away portion adjacent its closed end,said cut away portion being overlapped by said laterally projectingextension.

25. A flexible blade backing strip as defined in claim 15 wherein theextension of each strip member retractably projects laterally outwardlybeyond the outer edge of the other strip member which is in overlappedrelation therewith, the outer edge of each projecting extension beingformed with a notch, longitudinally opposed edge portions of said notchconstituting said pair of detents of said claw locking means, betweenwhich detents a claw may be snap-fitted by retraction of said projectingextensions.

26. A flexible blade backing strip as defined in claim 25 wherein saidprojecting extensions are resiliently biased to their projected positionby the associated closed ends of the respective strip members.

UNITED STATES PATENT OFFICE CERTIFICATE" OF CORRECTION Patent No.3,702,490 bated Nov. 14, 1972 InVent0r(s) William J. Quinlan andLawrence L. Huver It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

On Page 1 (cover page) between the listing of the inventors and thefiling date, insert the following:

Assignee Hastings Manufacturingioppany, Hastings; Michigan Signed andsealed this 17th day of April 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents F ORM PO-\ 050 (10-69) uscoMM-Dc dean-Pea v: U. 5. GOVERNMENTPRINTING OFFICE I!!! 0-3664,

1. For use in a windshield wiper blade assembly including an elongatedpressure uniT and an elongated detachable blade unit; a blade backingstrip resiliently flexible in a plane normal to its flat surfaces butsubstantially rigid against lateral deflection, adapted to support aresiliently flexible wiper element, said pressure unit including aplurality of claws adapted to slidably engage longitudinal edge portionsof said backing strip at longitudinally spaced points, said backingstrip including claw locking means and means adapted to cooperate withone of said claws for releasably locking the blade unit against slidingrelative to the pressure unit, said claw locking means comprising a pairof longitudinally spaced snap-fitting detents provided on at least onelongitudinal edge portion of said backing strip, the spacing of saiddetents corresponding substantially to the longitudinal dimension ofsaid one claw, and said one claw being movable longitudinally of thebacking strip to snap-fit into and out of a seated position between saiddetents, said blade backing strip comprising a pair of strip memberstransversely spaced and unconnected from end to end and adapted toreceive a wiper element therebetween, a closed end bridging said stripmembers together at one end of the backing strip, a pair of closed endsprovided on the respective strip members at the other end of the backingstrip, and an extension provided on each of said pair of closed ends intransversely spaced relation from the respective strip members, theclosed ends of the strip members with the extensions thereon beingmutually overlapped to close said other end of the backing strip andprevent longitudinal sliding thereof relative to a wiper element.
 2. Aflexible blade backing strip as defined in claim 1 wherein said pair oflongitudinally spaced detents are constituted by longitudinally opposingedge portions of a single notch provided in an outer longitudinal edgeof the backing strip.
 3. A flexible blade backing strip as defined inclaim 1 wherein at least one end of the backing strip is downturned andconstitutes stop means for a wiper element when assembled thereon.
 4. Aflexible blade backing strip as defined in claim 1 which is furthercharacterized in that it comprises a pair of strip members transverselyspaced and unconnected from end to end and adapted to receive a wiperelement therebetween, and a pair of closed ends bridging said stripmembers together adjacent the ends of a wiper element, said closed endsbeing downturned from the plane of the backing strip and constitutingstop means to prevent longitudinal sliding of the backing strip andwiper element relative to each other.
 5. A flexible blade backing stripas defined in claim 1 which is further characterized in that said closedends of said strip members are downturned from the plane of the backingstrip and constitute stop means to assist in preventing longitudinalsliding of the backing strip and wiper element relative to each other.6. A flexible blade backing strip as defined in claim 1 wherein each ofsaid extensions is narrower than its associated strip member and isdisposed at the inner edge of the other strip member when said pair ofclosed ends of the strip members are overlapped.
 7. A flexible bladebacking strip as defined in claim 1 which is further characterized inthat said strip members with said closed ends and with said extensionsare formed integrally from a single piece of material, the extension ofeach strip member overlapping but being unconnected to the other stripmember.
 8. A flexible blade backing strip as defined in claim 1 whereinsaid claw locking means are provided on the extension of at least one ofsaid strip members.
 9. A flexible blade backing strip as defined inclaim 1 wherein said claw locking means are provided on the extensionsof both of said strip members.
 10. A flexible blade backing strip asdefined in claim 1 wherein the extension of at least one of said stripmembers normally retractably projects laterally outwardly beyond theouter edge of the oTher strip member which is in overlapped relationtherewith, the outer edge of said projecting extension being formed witha notch, longitudinally opposed edge portions of said notch constitutingsaid pair of detents of said claw locking means, between which detents aclaw may be snap-fitted by retraction of said projecting extension. 11.A flexible blade backing strip as defined in claim 10 wherein saidprojecting extension is resiliently biased to its projected position bythe associated closed end of the associated strip member.
 12. A flexibleblade backing strip as defined in claim 10 wherein said other stripmember which is in overlapped relation with said projecting extension isprovided with a cut away portion adjacent its closed end, said cut awayportion being overlapped by said laterally projecting extension.
 13. Aflexible blade backing strip as defined in claim 1 wherein the extensionof each strip member retractably projects laterally outwardly beyond theouter edge of the other strip member which is in overlapped relationtherewith, the outer edge of each projecting extension being formed witha notch, longitudinally opposed edge portions of said notch constitutingsaid pair of detents of said claw locking means, between which detents aclaw may be snap-fitted by retraction of said projecting extensions. 14.A flexible blade backing strip as defined in claim 13 wherein saidprojecting extensions are resiliently biased to their projected positionby the associated closed ends of the respective strip members.
 15. Foruse in a windshield wiper blade assembly including an elongated pressureunit and an elongated detachable blade unit; a blade backing stripresiliently flexible in a plane normal to its flat surfaces butsubstantially rigid against lateral deflection, adapted to support aresiliently flexible wiper element, said pressure unit including aplurality of claws adapted to slidingly engage longitudinal edgeportions of said backing strip at longitudinally spaced points, saidbacking strip including claw locking means and means adapted tocooperate with one of said claws for releasably locking the blade unitagainst sliding relative to the pressure unit, said backing stripcomprising a pair of strip members which are transversely spaced andunconnected from end to end and adapted to receive a wiper elementtherebetween, a closed end bridging said strip members together at oneend of the backing strip, a pair of closed ends provided on therespective strip members at the other end of the backing strip, and anextension provided on each of said pair of closed ends in transverselyspaced relation from the respective strip members, the closed ends ofthe strip members with the extensions thereon being mutually overlappedto close said other end of the backing strip and prevent longitudinalsliding thereof relative to a wiper element.
 16. A flexible bladebacking strip as defined in claim 15 wherein at least one end of thebacking strip is downturned and constitutes stop means for a wiperelement when assembled thereon.
 17. A flexible blade backing strip asdefined in claim 15 which is further characterized in that said closedends of said strip members are downturned from the plane of the backingstrip and constitute stop means to assist in preventing longitudinalsliding of the backing strip and wiper element relative to each other.18. A flexible blade backing strip as defined in claim 15 wherein eachof said extensions is narrower than its associated strip member and isdisposed at the inner edge of the other strip member when said pair ofclosed ends of the strip members are overlapped.
 19. A flexible bladebacking strip as defined in claim 15 which is further characterized inthat said strip members with said closed ends and with said extensionsare formed integrally from a single piece of material, the extension ofeach strip member overlapping but being unconnected from the other stripmember.
 20. A flexible blade backing stRip as defined in claim 15wherein said claw locking means are provided on the extension of atleast one of said strip members.
 21. A flexible blade backing strip asdefined in claim 15 wherein said claw locking means are provided on theextensions of both of said strip members.
 22. A flexible blade backingstrip as defined in claim 15 wherein the extension of at least one ofsaid strip members retractably projects laterally outwardly beyond theouter edge of the other strip member which is in overlapped relationtherewith, the outer edge of said projecting extension being formed witha notch, longitudinally opposed edge portions of said notch constitutingsaid pair of detents of said claw locking means, between which detents aclaw may be snap-fitted by retraction of said projecting extension. 23.A flexible blade backing strip as defined in claim 22 wherein saidprojecting extension is resiliently biased to its projected position bythe associated closed end of the associated strip member.
 24. A flexibleblade backing strip as defined in claim 22 wherein said other stripmember which is in overlapped relation with said projecting extension isprovided with a cut away portion adjacent its closed end, said cut awayportion being overlapped by said laterally projecting extension.
 25. Aflexible blade backing strip as defined in claim 15 wherein theextension of each strip member retractably projects laterally outwardlybeyond the outer edge of the other strip member which is in overlappedrelation therewith, the outer edge of each projecting extension beingformed with a notch, longitudinally opposed edge portions of said notchconstituting said pair of detents of said claw locking means, betweenwhich detents a claw may be snap-fitted by retraction of said projectingextensions.
 26. A flexible blade backing strip as defined in claim 25wherein said projecting extensions are resiliently biased to theirprojected position by the associated closed ends of the respective stripmembers.